/* * twl4030_gpio.c -- access to GPIOs on TWL4030/TPS659x0 chips * * Copyright (C) 2006-2007 Texas Instruments, Inc. * Copyright (C) 2006 MontaVista Software, Inc. * * Code re-arranged and cleaned up by: * Syed Mohammed Khasim * * Initial Code: * Andy Lowe / Nishanth Menon * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include #include #include #include #include #include #include #include #include /* * The GPIO "subchip" supports 18 GPIOs which can be configured as * inputs or outputs, with pullups or pulldowns on each pin. Each * GPIO can trigger interrupts on either or both edges. * * GPIO interrupts can be fed to either of two IRQ lines; this is * intended to support multiple hosts. * * There are also two LED pins used sometimes as output-only GPIOs. * * FIXME code currently only handles the first IRQ line. */ static inline void activate_irq(int irq) { #ifdef CONFIG_ARM /* ARM requires an extra step to clear IRQ_NOREQUEST, which it * sets on behalf of every irq_chip. Also sets IRQ_NOPROBE. */ set_irq_flags(irq, IRQF_VALID); #else /* same effect on other architectures */ set_irq_noprobe(irq); #endif } static struct gpio_chip twl_gpiochip; static int twl4030_gpio_irq_base; static int twl4030_gpio_irq_end; /* genirq interfaces are not available to modules */ #ifdef MODULE #define is_module() true #else #define is_module() false #endif /* GPIO_CTRL Fields */ #define MASK_GPIO_CTRL_GPIO0CD1 BIT(0) #define MASK_GPIO_CTRL_GPIO1CD2 BIT(1) #define MASK_GPIO_CTRL_GPIO_ON BIT(2) /* Mask for GPIO registers when aggregated into a 32-bit integer */ #define GPIO_32_MASK 0x0003ffff /* Data structures */ static DEFINE_MUTEX(gpio_lock); /* store usage of each GPIO. - each bit represents one GPIO */ static unsigned int gpio_usage_count; /* protect what irq_chip modifies through its helper task */ static DEFINE_SPINLOCK(gpio_spinlock); /* shadow the imr register; updates are delayed */ static u32 gpio_imr_shadow; static bool gpio_pending_mask; /* bitmask of requests to set gpio irq trigger type */ static unsigned int gpio_pending_trigger; /* pointer to helper thread */ static struct task_struct *gpio_helper_thread; /* * Helper functions to read and write the GPIO ISR and IMR registers as * 32-bit integers. Functions return 0 on success, non-zero otherwise. * The caller must hold gpio_lock. */ /* NOTE: only the IRQ dispatcher may read ISR; reading it has * side effects, because of the clear-on-read mechanism (COR=1). */ static int gpio_read_isr(unsigned int *isr) { int ret; *isr = 0; ret = twl4030_i2c_read(TWL4030_MODULE_GPIO, (u8 *) isr, REG_GPIO_ISR1A, 3); le32_to_cpup(isr); *isr &= GPIO_32_MASK; return ret; } /* IMR is written only during initialization and * by request of the irq_chip code. */ static int gpio_write_imr(unsigned int imr) { imr &= GPIO_32_MASK; /* * The buffer passed to the twl4030_i2c_write() routine must have an * extra byte at the beginning reserved for its internal use. */ imr <<= 8; imr = cpu_to_le32(imr); return twl4030_i2c_write(TWL4030_MODULE_GPIO, (u8 *) &imr, REG_GPIO_IMR1A, 3); } /* * These are the irqchip methods for the TWL4030 GPIO interrupts. * Our IRQ handle method doesn't call these, but they will be called by * other routines such as setup_irq() and enable_irq(). They are called * with cpu interrupts disabled and with a lock on the irq_desc.lock * spinlock. This complicates matters, because accessing the TWL4030 GPIO * interrupt controller requires I2C bus transactions that can't be initiated * in this context. Our solution is to defer accessing the interrupt * controller to a kernel thread. */ static void twl4030_gpio_irq_ack(unsigned int irq) { /* NOP -- dispatcher acks when it reads ISR */ } static void twl4030_gpio_irq_mask(unsigned int irq) { int gpio = irq - twl4030_gpio_irq_base; u32 mask = 1 << gpio; unsigned long flags; spin_lock_irqsave(&gpio_spinlock, flags); gpio_pending_mask = true; gpio_imr_shadow |= mask; if (gpio_helper_thread && gpio_helper_thread->state != TASK_RUNNING) wake_up_process(gpio_helper_thread); spin_unlock_irqrestore(&gpio_spinlock, flags); } static void twl4030_gpio_irq_unmask(unsigned int irq) { int gpio = irq - twl4030_gpio_irq_base; u32 mask = 1 << gpio; unsigned long flags; spin_lock_irqsave(&gpio_spinlock, flags); gpio_pending_mask = true; gpio_imr_shadow &= ~mask; if (gpio_helper_thread && gpio_helper_thread->state != TASK_RUNNING) wake_up_process(gpio_helper_thread); spin_unlock_irqrestore(&gpio_spinlock, flags); } static int twl4030_gpio_irq_set_type(unsigned int irq, unsigned trigger) { struct irq_desc *desc = irq_desc + irq; int gpio = irq - twl4030_gpio_irq_base; unsigned long flags; trigger &= IRQ_TYPE_SENSE_MASK; if (trigger & ~IRQ_TYPE_EDGE_BOTH) return -EINVAL; if ((desc->status & IRQ_TYPE_SENSE_MASK) == trigger) return 0; desc->status &= ~IRQ_TYPE_SENSE_MASK; desc->status |= trigger; spin_lock_irqsave(&gpio_spinlock, flags); gpio_pending_trigger |= (1 << gpio); if (gpio_helper_thread && gpio_helper_thread->state != TASK_RUNNING) wake_up_process(gpio_helper_thread); spin_unlock_irqrestore(&gpio_spinlock, flags); return 0; } static struct irq_chip twl4030_gpio_irq_chip = { .name = "twl4030", .ack = twl4030_gpio_irq_ack, .mask = twl4030_gpio_irq_mask, .unmask = twl4030_gpio_irq_unmask, .set_type = twl4030_gpio_irq_set_type, }; /* * To configure TWL4030 GPIO module registers */ static inline int gpio_twl4030_write(u8 address, u8 data) { return twl4030_i2c_write_u8(TWL4030_MODULE_GPIO, data, address); } /* * To read a TWL4030 GPIO module register */ static inline int gpio_twl4030_read(u8 address) { u8 data; int ret = 0; ret = twl4030_i2c_read_u8(TWL4030_MODULE_GPIO, &data, address); return (ret < 0) ? ret : data; } /* * twl4030 GPIO request function */ int twl4030_request_gpio(int gpio) { int ret = 0; if (unlikely(gpio >= TWL4030_GPIO_MAX)) return -EPERM; ret = gpio_request(twl_gpiochip.base + gpio, NULL); if (ret < 0) return ret; mutex_lock(&gpio_lock); if (gpio_usage_count & BIT(gpio)) { ret = -EBUSY; } else { /* First time usage? - switch on GPIO module */ if (!gpio_usage_count) { ret = gpio_twl4030_write(REG_GPIO_CTRL, MASK_GPIO_CTRL_GPIO_ON); } if (!ret) gpio_usage_count |= BIT(gpio); else gpio_free(twl_gpiochip.base + gpio); } mutex_unlock(&gpio_lock); return ret; } EXPORT_SYMBOL(twl4030_request_gpio); /* * TWL4030 GPIO free module */ int twl4030_free_gpio(int gpio) { int ret = 0; if (unlikely(gpio >= TWL4030_GPIO_MAX)) return -EPERM; mutex_lock(&gpio_lock); if ((gpio_usage_count & BIT(gpio)) == 0) { ret = -EPERM; } else { gpio_usage_count &= ~BIT(gpio); gpio_free(twl_gpiochip.base + gpio); } /* Last time usage? - switch off GPIO module */ if (ret == 0 && !gpio_usage_count) ret = gpio_twl4030_write(REG_GPIO_CTRL, 0x0); mutex_unlock(&gpio_lock); return ret; } EXPORT_SYMBOL(twl4030_free_gpio); static int twl4030_set_gpio_direction(int gpio, int is_input) { u8 d_bnk = gpio >> 3; u8 d_msk = BIT(gpio & 0x7); u8 reg = 0; u8 base = REG_GPIODATADIR1 + d_bnk; int ret = 0; mutex_lock(&gpio_lock); ret = gpio_twl4030_read(base); if (ret >= 0) { if (is_input) reg = ret & ~d_msk; else reg = ret | d_msk; ret = gpio_twl4030_write(base, reg); } mutex_unlock(&gpio_lock); return ret; } static int twl4030_set_gpio_dataout(int gpio, int enable) { u8 d_bnk = gpio >> 3; u8 d_msk = BIT(gpio & 0x7); u8 base = 0; if (enable) base = REG_SETGPIODATAOUT1 + d_bnk; else base = REG_CLEARGPIODATAOUT1 + d_bnk; return gpio_twl4030_write(base, d_msk); } int twl4030_get_gpio_datain(int gpio) { u8 d_bnk = gpio >> 3; u8 d_off = gpio & 0x7; u8 base = 0; int ret = 0; if (unlikely((gpio >= TWL4030_GPIO_MAX) || !(gpio_usage_count & BIT(gpio)))) return -EPERM; base = REG_GPIODATAIN1 + d_bnk; ret = gpio_twl4030_read(base); if (ret > 0) ret = (ret >> d_off) & 0x1; return ret; } EXPORT_SYMBOL(twl4030_get_gpio_datain); static int twl4030_set_gpio_edge_ctrl(int gpio, int edge) { u8 c_bnk = gpio >> 2; u8 c_off = (gpio & 0x3) * 2; u8 c_msk = 0; u8 reg = 0; u8 base = 0; int ret = 0; base = REG_GPIO_EDR1 + c_bnk; if (edge & IRQ_TYPE_EDGE_RISING) c_msk |= BIT(c_off + 1); if (edge & IRQ_TYPE_EDGE_FALLING) c_msk |= BIT(c_off); mutex_lock(&gpio_lock); ret = gpio_twl4030_read(base); if (ret >= 0) { /* clear the previous rising/falling values */ reg = (u8) ret; reg &= ~(0x3 << c_off); reg |= c_msk; ret = gpio_twl4030_write(base, reg); } mutex_unlock(&gpio_lock); return ret; } /* * Configure debounce timing value for a GPIO pin on TWL4030 */ int twl4030_set_gpio_debounce(int gpio, int enable) { u8 d_bnk = gpio >> 3; u8 d_msk = BIT(gpio & 0x7); u8 reg = 0; u8 base = 0; int ret = 0; if (unlikely((gpio >= TWL4030_GPIO_MAX) || !(gpio_usage_count & BIT(gpio)))) return -EPERM; base = REG_GPIO_DEBEN1 + d_bnk; mutex_lock(&gpio_lock); ret = gpio_twl4030_read(base); if (ret >= 0) { if (enable) reg = ret | d_msk; else reg = ret & ~d_msk; ret = gpio_twl4030_write(base, reg); } mutex_unlock(&gpio_lock); return ret; } EXPORT_SYMBOL(twl4030_set_gpio_debounce); #if 0 /* * Configure Card detect for GPIO pin on TWL4030 * * This means: VMMC1 or VMMC2 is enabled or disabled based * on the status of GPIO-0 or GPIO-1 pins (respectively). */ int twl4030_set_gpio_card_detect(int gpio, int enable) { u8 reg = 0; u8 msk = (1 << gpio); int ret = 0; /* Only GPIO 0 or 1 can be used for CD feature.. */ if (unlikely((gpio >= TWL4030_GPIO_MAX) || !(gpio_usage_count & BIT(gpio)) || (gpio >= TWL4030_GPIO_MAX_CD))) { return -EPERM; } mutex_lock(&gpio_lock); ret = gpio_twl4030_read(REG_GPIO_CTRL); if (ret >= 0) { if (enable) reg = (u8) (ret | msk); else reg = (u8) (ret & ~msk); ret = gpio_twl4030_write(REG_GPIO_CTRL, reg); } mutex_unlock(&gpio_lock); return ret; } #endif /* MODULE FUNCTIONS */ /* * gpio_helper_thread() is a kernel thread that is awakened by irq_chip * methods to update IRQ masks and trigger modes. * * We must do this in a thread rather than in irq_chip methods because of the * need to access the TWL4030 via the I2C bus. Note that we don't need to be * concerned about race conditions where the request to unmask a GPIO interrupt * has already been cancelled before this thread does the unmasking. If a GPIO * interrupt is improperly unmasked, then the IRQ handler for it will mask it * when an interrupt occurs. */ static int twl4030_gpio_helper_thread(void *dev) { current->flags |= PF_NOFREEZE; while (!kthread_should_stop()) { int irq; bool do_mask; u32 local_imr; unsigned int gpio_trigger; spin_lock_irq(&gpio_spinlock); do_mask = gpio_pending_mask; gpio_pending_mask = false; local_imr = gpio_imr_shadow; gpio_trigger = gpio_pending_trigger; gpio_pending_trigger = 0; spin_unlock_irq(&gpio_spinlock); if (do_mask) { int status = gpio_write_imr(local_imr); if (status) dev_err(dev, "write IMR err %d\n", status); } for (irq = twl4030_gpio_irq_base; gpio_trigger; gpio_trigger >>= 1, irq++) { struct irq_desc *desc; unsigned type; if (!(gpio_trigger & 0x1)) continue; desc = irq_desc + irq; spin_lock_irq(&desc->lock); type = desc->status & IRQ_TYPE_SENSE_MASK; spin_unlock_irq(&desc->lock); twl4030_set_gpio_edge_ctrl(irq - twl4030_gpio_irq_base, type); } spin_lock_irq(&gpio_spinlock); if (!gpio_pending_mask && !gpio_pending_trigger) set_current_state(TASK_INTERRUPTIBLE); spin_unlock_irq(&gpio_spinlock); schedule(); } set_current_state(TASK_RUNNING); return 0; } /* * do_twl4030_gpio_module_irq() is the desc->handle method for the twl4030 gpio * module interrupt. It executes in kernel thread context. * This is a chained interrupt, so there is no desc->action method for it. * We query the gpio module interrupt controller in the twl4030 to determine * which gpio lines are generating interrupt requests, and then call the * desc->handle method for each gpio that needs service. * On entry, cpu interrupts are disabled. */ static void do_twl4030_gpio_module_irq(unsigned int irq, irq_desc_t *desc) { int gpio_irq; unsigned int gpio_isr; /* PIH irqs like this can't be individually masked or acked ... * so we don't even call the PIH irq_chip stub methods. */ local_irq_enable(); if (gpio_read_isr(&gpio_isr)) gpio_isr = 0; local_irq_disable(); for (gpio_irq = twl4030_gpio_irq_base; 0 != gpio_isr; gpio_isr >>= 1, gpio_irq++) { if (gpio_isr & 0x1) generic_handle_irq(gpio_irq); } } /*----------------------------------------------------------------------*/ static int twl_direction_in(struct gpio_chip *chip, unsigned offset) { return twl4030_set_gpio_direction(offset, 1); } static int twl_get(struct gpio_chip *chip, unsigned offset) { int status = twl4030_get_gpio_datain(offset); return (status < 0) ? 0 : status; } static int twl_direction_out(struct gpio_chip *chip, unsigned offset, int value) { twl4030_set_gpio_dataout(offset, value); return twl4030_set_gpio_direction(offset, 0); } static void twl_set(struct gpio_chip *chip, unsigned offset, int value) { twl4030_set_gpio_dataout(offset, value); } static int twl_to_irq(struct gpio_chip *chip, unsigned offset) { /* NOTE: assumes IRQs are set up ... */ return twl4030_gpio_irq_base + offset; } static struct gpio_chip twl_gpiochip = { .label = "twl4030", .owner = THIS_MODULE, .direction_input = twl_direction_in, .get = twl_get, .direction_output = twl_direction_out, .set = twl_set, .to_irq = twl_to_irq, .can_sleep = 1, }; /*----------------------------------------------------------------------*/ static int __devinit gpio_twl4030_pulls(u32 ups, u32 downs) { u8 message[6]; unsigned i, gpio_bit; /* For most pins, a pulldown was enabled by default. * We should have data that's specific to this board. */ for (gpio_bit = 1, i = 1; i < 6; i++) { u8 bit_mask; unsigned j; for (bit_mask = 0, j = 0; j < 8; j += 2, gpio_bit <<= 1) { if (ups & gpio_bit) bit_mask |= 1 << (j + 1); else if (downs & gpio_bit) bit_mask |= 1 << (j + 0); } message[i] = bit_mask; } return twl4030_i2c_write(TWL4030_MODULE_GPIO, message, REG_GPIOPUPDCTR1, 5); } static int gpio_twl4030_remove(struct platform_device *pdev); static int __devinit gpio_twl4030_probe(struct platform_device *pdev) { struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data; int ret; int irq = 0; /* All GPIO interrupts are initially masked */ gpio_pending_mask = false; gpio_imr_shadow = GPIO_32_MASK; ret = gpio_write_imr(gpio_imr_shadow); twl4030_gpio_irq_base = pdata->irq_base; twl4030_gpio_irq_end = pdata->irq_end; if ((twl4030_gpio_irq_end - twl4030_gpio_irq_base) > 0) { if (is_module()) { dev_err(&pdev->dev, "can't dispatch IRQs from modules\n"); goto no_irqs; } if (twl4030_gpio_irq_end > NR_IRQS) { dev_err(&pdev->dev, "last IRQ is too large: %d\n", twl4030_gpio_irq_end); return -EINVAL; } } else { dev_notice(&pdev->dev, "no IRQs being dispatched\n"); goto no_irqs; } if (!ret) { /* * Create a kernel thread to handle deferred operations on gpio * interrupts. */ gpio_helper_thread = kthread_create(twl4030_gpio_helper_thread, &pdev->dev, "twl4030 gpio"); if (!gpio_helper_thread) { dev_err(&pdev->dev, "could not create helper thread!\n"); ret = -ENOMEM; } } if (!ret) { /* install an irq handler for each of the gpio interrupts */ for (irq = twl4030_gpio_irq_base; irq < twl4030_gpio_irq_end; irq++) { set_irq_chip_and_handler(irq, &twl4030_gpio_irq_chip, handle_edge_irq); activate_irq(irq); } /* gpio module IRQ */ irq = platform_get_irq(pdev, 0); /* COR=1 means irqs are acked by reading ISR * PENDDIS=0 means pending events enabled * EXCLEN=0 means route to both irq lines */ gpio_twl4030_write(REG_GPIO_SIH_CTRL, TWL4030_SIH_CTRL_COR_MASK); /* * Install an irq handler to demultiplex the gpio module * interrupt. */ set_irq_chained_handler(irq, do_twl4030_gpio_module_irq); wake_up_process(gpio_helper_thread); dev_info(&pdev->dev, "IRQ %d chains IRQs %d..%d\n", irq, twl4030_gpio_irq_base, twl4030_gpio_irq_end - 1); } no_irqs: if (!ret) { /* * NOTE: boards may waste power if they don't set pullups * and pulldowns correctly ... default for non-ULPI pins is * pulldown, and some other pins may have external pullups * or pulldowns. Careful! */ ret = gpio_twl4030_pulls(pdata->pullups, pdata->pulldowns); if (ret) dev_dbg(&pdev->dev, "pullups %.05x %.05x --> %d\n", pdata->pullups, pdata->pulldowns, ret); twl_gpiochip.base = pdata->gpio_base; twl_gpiochip.ngpio = TWL4030_GPIO_MAX; twl_gpiochip.dev = &pdev->dev; ret = gpiochip_add(&twl_gpiochip); if (ret < 0) { dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret); twl_gpiochip.ngpio = 0; gpio_twl4030_remove(pdev); } else if (pdata->setup) { int status; status = pdata->setup(&pdev->dev, pdata->gpio_base, TWL4030_GPIO_MAX); if (status) dev_dbg(&pdev->dev, "setup --> %d\n", status); } } return ret; } static int __devexit gpio_twl4030_remove(struct platform_device *pdev) { struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data; int status; int irq; if (pdata->teardown) { status = pdata->teardown(&pdev->dev, pdata->gpio_base, TWL4030_GPIO_MAX); if (status) { dev_dbg(&pdev->dev, "teardown --> %d\n", status); return status; } } status = gpiochip_remove(&twl_gpiochip); if (status < 0) return status; if (is_module() || (twl4030_gpio_irq_end - twl4030_gpio_irq_base) <= 0) return 0; /* uninstall the gpio demultiplexing interrupt handler */ irq = platform_get_irq(pdev, 0); set_irq_handler(irq, NULL); /* uninstall the irq handler for each of the gpio interrupts */ for (irq = twl4030_gpio_irq_base; irq < twl4030_gpio_irq_end; irq++) set_irq_handler(irq, NULL); /* stop the gpio helper kernel thread */ if (gpio_helper_thread) { kthread_stop(gpio_helper_thread); gpio_helper_thread = NULL; } return 0; } /* Note: this hardware lives inside an I2C-based multi-function device. */ MODULE_ALIAS("platform:twl4030_gpio"); static struct platform_driver gpio_twl4030_driver = { .driver.name = "twl4030_gpio", .driver.owner = THIS_MODULE, .probe = gpio_twl4030_probe, .remove = __devexit_p(gpio_twl4030_remove), }; static int __init gpio_twl4030_init(void) { return platform_driver_register(&gpio_twl4030_driver); } subsys_initcall(gpio_twl4030_init); static void __exit gpio_twl4030_exit(void) { platform_driver_unregister(&gpio_twl4030_driver); } module_exit(gpio_twl4030_exit); MODULE_AUTHOR("Texas Instruments, Inc."); MODULE_DESCRIPTION("GPIO interface for TWL4030"); MODULE_LICENSE("GPL");